1. Field of the Invention
The present invention relates to a post-mounted interior mirror for a motor vehicle and in particular, to an antiglare mirror apparatus mounted in a vehicle compartment with high antiglare performance using a mirror member made of an electrochromic element.
2. Related Art of the Invention
An interior mirror for a motor vehicle equipped for viewing a vehicle behind the vehicle is filled with glare when a headlight from the following vehicle is reflected in the interior mirror during driving at night and therefore, various kinds of antiglare mirrors have been proposed (Japanese Issued Patent Publication No. 2722590, Japanese Unexamined Patent Publication No. 8-106110, Japanese Issued Patent Publication No. 2858006).
These inner mirrors utilize an electrochromic element colored by oxidation-reduction reaction due to voltage impression where a mirror member is an electrochromic element made by laminating in order a light transmission electrode material, an antiglare material having an electrochromic layer, and a light reflective electrode material from the surface side.
Also there is another proposal that a coloring amount (namely, level of antiglare) of the mirror member is controlled manually or automatically by controlling electric energy for driving an electrochromic element. It is known that as a method of automatically controlling the coloring amount, an energy supply amount to the electrochromic element is controlled based upon information of surrounding light and incident light from the rear detected by a sensor, thereby to control the color amount (Japanese Unexamined Patent Publication No. 9-24768). Where the electrochromic element is driven in the coloring direction, the glare is restrained due to reduction in reflectance of the mirror member.
In Japanese Unexamined Patent Publication No. 5-286398, an antiglare apparatus that can be mounted to an inner mirror mounted beforehand is proposed where this apparatus has a transmission base made by laminating a transmission electrode material on both surfaces of an electrochromic layer and the transmission base is mounted to the surface of the inner mirror mounted beforehand. Accordingly, the electrochromic element is colored by voltage impression and the reflectance of the inner mirror is lowered.
On the other hand, it is known that when a visibility region to the rear is expected to be enlarged, a replacement mirror is mounted to a pre-mounted mirror (Japanese Issued Utility Publication No. 3021443, Japanese Unexamined Utility Publication No. 59-42740, No. 59-42741, No.58-184352, No.57-63302). The replacement mirror of these Publications is mounted to the pre-mounted mirror so as to cover the mirror member on the surface thereof and a mounting member for holding the pre-mounted mirror in both an upper edge portion and a lower edge portion thereof is mounted to a rear side of a holder.
However, an antiglare mirror disclosed in Japanese Unexamined Patent Publication No.9-24768 is mounted in a factory when a new car is manufactured and therefore, it is not so easy for ordinary people to replace a pre-mounted mirror with the antiglare mirror because a large alteration in a vehicle interior is required.
In an antiglare apparatus disclosed in Japanese Unexamined Patent Publication No. 5-286393, a transparent base is used and therefore, it does not function as a mirror. Also, since a mirror is mounted on a mirror member of a pre-mounted mirror and light is reflected using the mirror member thereof, the visibility region thereof can not be enlarged more than the pre-mounted mirror. Further, if an opaque object is inserted between the transparent base of the antiglare apparatus and the mirror member of the pre-mounted mirror, it will not work. Accordingly, in this apparatus a control circuit for driving the electrochromic element, a switch, a sensor and the like can not be arranged inside the holder.
Therefore, an antiglare mirror apparatus mounted in a vehicle compartment according to the present invention includes a mirror member having an electrochromic element that disposes an antiglare material including an electrochromic layer, a light transmission electrode material and a light reflective electrode material on both sides of the antiglare material, a power source member that supplies electric energy to drive the electrochromic element, a signal generator that generates a driving electric signal of the electrochromic element, a control circuit that controls the drive-electric energy of the electrochromic element based upon the driving electric signal, and a holder that holds the mirror member and is detachably mounted to a facility in a vehicle compartment.
According to the above arrangement, the energy from the power source member is supplied to the antiglare material through the light transmission electrode material and the light reflective electrode material so that the antiglare material is colored. When light transmits the antiglare material, the spectrum thereof with a predetermined wave length is absorbed therein and the resultant light is reflected in the light reflective electrode material. Therefore, reflectance of the mirror member is lowered and antiglare performance increases. This mirror member holder is removably connected to the facility in a vehicle compartment, and thereby an alteration is not needed for mounting the mirror member to the vehicle compartment.